This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A364215 #7 Jul 15 2023 05:52:53 %S A364215 1,2,1,2,3,2,3,2,3,4,1,2,3,2,3,4,3,4,3,4,5,2,3,2,3,4,3,4,3,4,5,2,3,4, %T A364215 3,4,5,4,5,4,5,6,1,2,3,2,3,4,3,4,3,4,5,2,3,4,3,4,5,4,5,4,5,6,3,4,3,4, %U A364215 5,4,5,4,5,6,3,4,5,4,5,6,5,6,5,6,7,2,3 %N A364215 The number of 1's in the canonical representation of n as a sum of distinct Jacobsthal numbers (A280049). %H A364215 Amiram Eldar, <a href="/A364215/b364215.txt">Table of n, a(n) for n = 1..10000</a> %F A364215 a(n) = A007953(A280049(n)). %F A364215 a(n) = A000120(A003159(n)). %F A364215 a(A007583(n)) = 1. %t A364215 DigitCount[Select[Range[200], EvenQ[IntegerExponent[#, 2]] &], 2, 1] %o A364215 (PARI) s(n) = if(n < 2, n > 0, n = s(n-1); until(valuation(n, 2)%2 == 0, n++); n); \\ A003159 %o A364215 a(n) = hammingweight(s(n)); %Y A364215 Cf. A000120, A003159, A007583, A007953, A280049. %K A364215 nonn,base,easy %O A364215 1,2 %A A364215 _Amiram Eldar_, Jul 14 2023